Multi-dimensional micro-electromechanical assemblies and method of making same

Abstract

A multi-dimensional, micro-electromechanical assembly and the method of fabricating same. The invention enables an assembly of three-dimensional (3D) microelectromechanical systems (MEMS) using surface tension or shrinkage self assembly. That is, the invention provides a surface tension self assembly technique for rotating a MEMS element with a controlled amount of deformation to a selected angle out of the plane of a substrate. In accordance with the inventive method, multi-dimensional, micro-electromechanical assemblies are fabricated by providing a phase change material on at least one substantially planar structure mounted in a first orientation. A phase change is induced in the phase change material whereby the phase change material changes from a first state, in which the structure is disposed in the first orientation, to a second state, in which the structure is disposed in a second orientation. The MEMS elements may be fabricated using conventional surface micromachining techniques. In the illustrative embodiment, each MEMS element is attached to a substrate by at least one hinge which allows rotation of the MEMS element out of the plane of the substrate to a selected angle. To enable mass assembly of the MEMS elements, the MEMS elements are rotated to the selected angle using either surface tension forces of a liquid phase change material or shrinkage of a solid phase change material. In the illustrative embodiment, the phase change material is solder and the step of inducing a phase change in the phase change material includes the step up applying heat.

What is claimed is:  
     
         1 . A method for fabricating a multi-dimensional, micro-electromechanical assembly comprising the steps of: 
 providing a surface;    mounting at least one substantially planar structure on said surface in a first orientation;    providing a phase change material on said structure; and    inducing a phase change in said phase change material whereby said phase change material changes from a first state, in which said structure is disposed in said first orientation, to a second state, in which said structure is disposed in a second orientation.    
     
     
         2 . The invention of  claim 1  wherein said phase change material is solder.  
     
     
         3 . The invention of  claim 2  wherein said step of inducing a phase change in said phase change material includes the step up applying heat.  
     
     
         4 . The invention of  claim 1  wherein the step of mounting at least one substantially planar structure includes the step of mounting plural substantially planar structures in said substantially parallel orientation.  
     
     
         5 . The invention of  claim 1  wherein said first orientation is substantially parallel with respect to at least one axis relative to said surface and said second orientation is substantially nonparallel with respect to said axis relative to said surface.  
     
     
         6 . The invention of  claim 1  wherein said surface is a substrate.  
     
     
         7 . The invention of  claim 1  wherein said surface is a structure.  
     
     
         8 . A method for fabricating a multi-dimensional, micro-electromechanical assembly comprising the steps of: 
 providing a surface;    providing a phase change material on said surface;    mounting at least one substantially planar structure on said surface and at least partially on said phase change material in a first orientation; and    inducing a phase change in said phase change material whereby said phase change material changes from a first state, in which said structure is disposed in said first orientation, to a second state, in which said structure is disposed in a second orientation.    
     
     
         9 . A multi-dimensional, micro-electromechanical assembly comprising: 
 a surface;    at least one substantially planar structure mounted on said surface in a first orientation; and    a phase change material disposed on said structure;    whereby when said phase change material changes from a first state to a second state, the orientation of said structure is changed from said first orientation to a second orientation.    
     
     
         10 . The invention of  claim 9  wherein said phase change material is solder.  
     
     
         11 . The invention of  claim 9  including plural planar structures mounted in said substantially parallel orientation.  
     
     
         12 . The invention of  claim 11  further including a hinge connecting each of said planar structures to said surface.  
     
     
         13 . The invention of  claim 12  further including a mechanical rotation limiter.  
     
     
         14 . The invention of  claim 13  wherein said mechanical rotation limiter is a kickstand.  
     
     
         15 . The invention of  claim 13  wherein said mechanical rotation limiter is a lock.  
     
     
         16 . The invention of  claim 9  wherein said first orientation is substantially parallel with respect to at least one axis relative to said surface and said second orientation is substantially nonparallel with respect to said axis relative to said surface.  
     
     
         17 . The invention of  claim 9  wherein said surface is a substrate.  
     
     
         18 . The invention of  claim 9  wherein said surface is a structure.  
     
     
         19 . A multi-dimensional, micro-electromechanical assembly comprising: 
 a surface;    a phase change material disposed on said surface; and    at least one substantially planar structure mounted on said surface and at least partially on said phase change material in a first orientation;    whereby when said phase change material changes from a first state to a second state, the orientation of said structure is changed from said first orientation to a second orientation.    
     
     
         20 . A multi-dimensional, micro-electromechanical assembly comprising: 
 a substrate;    plural substantially planar structures mounted at least partially on said substrate in a first orientation; and    solder disposed in predetermined positions on said structures;    whereby when said solder changes from a first state to a second state, the orientation of said structures are changed from said first orientation to a second orientation, said first orientation being substantially parallel with respect to at least one axis relative to said substrate and said second orientation being substantially nonparallel with respect to said axis relative to said substrate.